On two occasions in Behar the Torah instructs us not to afflict our fellow Jew. In the first instance, the Torah states: "When you sell an item to one of your people or buy from one of your people, a man should not afflict his brother." (1) A few verses later, the Torah seemingly repeats itself: "Do not afflict your people and fear your God, because I am HaShem, Your God." (2) The Gemara explain that there are two different types of onaah (affliction); the first verse refers to onaat mammon - affliction relating to money.(3) The second relates to onaat devarim - hurting someone through words.(4) In general the Rabbis do not compare two specific Mitzvot and say that one is greater than another, however, in this instance they compare the two forms of affliction. Initially, one would think that onaat mammon is more severe than onaat devarim because when a person is hurt verbally he does not lose any tangible object, however when he is afflicted financially then he suffers a real loss.
However, surprisingly, the Gemara says that onaat devarim is considered a greater sin than onaat mammon for three different reasons. Firstly, with regard to onaat devarim the verse says, and you should fear your G-d" but it omits this when discussing onaat mammon. The Maharsha explains that people are more likely to notice when someone is trying to commit onaat mammon but that it is far easier to conceal one's true intentions to harm people verbally. Someone who harms other financially is aware that people will likely recognize what he is doing but continues regardless. He shows a lack of fear of God, because he is unconcerned that God is totally aware of his actions but he also demonstrates no fear of what people think of his actions. A person who harms people in a concealed way demonstrates that he fears people more than God - he is only concerned that people not think he is a cruel person, but he is unconcerned that God knows his true intentions. He is considered on a lower level than one who harms financially because he demonstrates greater concern for the opinion of other people than for God.(5)
Secondly, the Gemara says that onaat mammon merely harms people's property, whereas onaat devarim is worse because it harms someone's very being. This particularly refers to a person's emotional well-being - the damage done to them by a careless word can penetrate to their very essence. A frightening example of this is related by Rav Dov Brezak: He relates how a well-respected man in his forties required counseling because of a traumatic childhood experience - on one occasion his mother called him 'tamei' (impure). That single labeling damaged him so deeply that it stayed with him for the rest of his life. This provides ample indication that harmful words can cause untold damage.
The Gemara continues with a third aspect in which onaat devarim is worse than onaat mammon - if a person deceitfully extracts money from his fellow he can repair the damage by simply returning that which he unjustly took. However, when one harms someone else with words, no amount of apologizing can change the past - those words can never be taken back. It is a common occurrence in relationships, especially in marriage, that a few insensitive words have long-lasting damage and that damage can never be fully healed because those words can never be fully taken back. Perhaps a corollary of this aspect of the severity of onaat devarim is that once harmful words are spoken they can rapidly have a 'domino effect' whereby the consequences of these few words can be so far-reaching that it is impossible to ever undo the damage those words had done.
It is very clear from the Gemara how serious the sin of onaat devarim can be, moreover it is a very difficult Mitzva to observe properly - we are constantly involved in conversation with other people and it is very easy to hurt their feelings through a thoughtless statement. Moreover, because we speak so much we can forget how serious a sin it is to hurt other people's feelings. The Chazon Ish once witnessed a man strongly rebuke his young son for moving something on Shabbat that may have been muktza (an item that it is prohibited to move on Shabbat). The Chazon Ish told the man that his son may have transgressed a Rabbinical Mitzva, but that the father had definitely transgressed the Torah mitzvah of not saying hurtful words.
One technique to help be more watchful of this mitzvah is to develop the attitude that we should be just as careful in it as in all other mitzvot such as kashrus - we would never eat something without being certain that it was permitted to eat it. So to, we need to try to develop a sense of vigilance that what we are about to release from our mouth is permitted. The best way of doing this is by learning the laws and ideas behind it.(6)
It is instructive to end with one final saying of the Chazon Ish - he used to remark that one of the greatest possible sources of joy is that he lived his whole life without causing pain to his fellow Jew. May we all be merit to only do good with our speech.
1. Behar, 25:14.
2. Behar, 25:18.
3. Onaat mammon consists of deliberately selling an item for an extortionately high amount or deliberately buying an item for an exceedingly low price.
4. Bava Metsia, 58b.
5. Maharsha, Bava Metsia, 58b. He compares this to the saying that a ganav (someone who steals quietly) is worse than a gazlan (who steals in public) because the ganav steals in private because he is worried about people seeing him steal but has no concern that God knows he is stealing, whereas a gazlan steals in public and shows equal disregard for people and God.
6. The Sefer Mishpatey Shalom, Ch. 7 is a good source for the laws pertaining to onaas devarim.